The references cited herein are not admitted to be prior art to the claimed invention.
γ-Aminobutric acid (GABA) is a major inhibitory neurotransmitter present in insects and vertebrates. Vertebrate central nervous system GABA receptors have been divided into subtype GABAA and subtype GABAB. GABAA receptors give rise to GABA gated Cl− currents and contain modulatory sites for benzodiazepines, barbiturates and steroids. GABAB receptors mediate effects of GABA on K+ and Ca2+ conductances through interactions with G proteins. (Rauh et al., TiPS 11:325-329, 1990.)
Nucleic acid encoding for GABA receptors have been cloned from different sources including vertebrates and insects. Examples of some vertebrate GABA receptors are discussed by Olsen et al., FASEB J. 4:1469-1480, 1990. Examples of insect GABA receptor are provided in Soderlund et al., U.S. Pat. No. 5,487,976, Tomalski et al., U.S. Pat. No. 5,854,002, Wingate et al., U.S. Pat. No. 5,767,262 and Roush et al., International Publication Number WO 93/07161.
An example of a GABA receptor obtained from an insect is the dieldrin resistant GABA receptor (Rdl). Nucleic acid encoding for Rdl has been cloned from Drosophila. (Ffrench-Constant et al., Proc. Natl. Acad. Sci. USA 88:7209-7213, 1991, and Roush et al., International Publication Number WO 93/07161.) Insects containing an A302S mutation in the rdl gene are resistant to different GABA antagonists including cyclodienes, picrotoxinin and fibronil. (Ffrench-Constant et al., Nature 363:449-451, 1993; Buckingham et al., Neuroscience Letters 181:137-140, 1994; and Hosie et al., British Journal of Pharmacology 115:909-912, 1995.)